Trickle irrigation unit

ABSTRACT

An emitting unit for use in trickle irrigation systems comprises a pair of telescopic members, one of the members being formed with a continuous groove forming with the other member a large cross-section flow path having continuous direction-changing bends.

United States Patent 1191 Gilaad Feb. 19, 1974- 15 1 TRICKLE IRRIGATION UNIT 3,426,544 2/1969 Curtis 61 13 3,604,728 9/1971 Symcha et al. 285/14 [76] lnvemor- 3' Yechezklel Tel 3,521,753 7/1970 Schoening 210/483 x AVIV, Israel 1,335,899 4 1920 Kahlenberg 210 497 x 1 3,420,064 1/1969 Blass et al 61/13 [22] May 1972 2,981,072 4/1961 Brewington 61 11 [21] Appl. No.: 253,452

Primary Examiner-Mervin Stein [30] Foreign Application Priority Data I Assistant Examiner-David H. Corbin May 23, 1971 Israel 36901 52 11.8. C1 61/12, 47/485, 285/14 A T A T [51] Int. C1 E02b 13/00 [58] Field 61 Search 61/10, 11, 12, 13; 210/483, 2x222: i 832 2;:fiz ggjs gg ffifi 210/497; 47/48 S; 285/5 4 members being formed with a continuous groove forming with the other member a large cross-section [56] U TE ::S ;ZrENTS flow path having continuous direction-changing bends. 3,403,519 10/1968 Balko 61/13 6 Claims, 10 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to irrigation systems, and more particularly to so called'drip, or trickle, irrigation units. In such systems the dispensing or emitting unit (as it is sometimes called) is destined to ensure a slow trickle or driplike rate of discharge of water through the said unit.

Usually the water is supplied to the dispensing or emitting units through a continuous pipeline, which may be a permanent rigid metal or plastic line or a flexible plastic hose which can be installed at a place and removed at will to be set up at another point. The emitting units are inserted in the line at regular intervals, or are attached thereto at such intervals so that water being conducted through the pipeline trickles or drips out at the points where the emitting units are provided, while the greater part of the water continues in the pipeline to the next dispensing or emitting unit, where again a small quantity of water is continuously dispensed in a trickle or driplike fashion, and so on to the next dispensing unit.

In designing the dispensing or emitting units, the main problems to be solved are the following:

a. a slow uniform dripping or trickle of water has to be ensured;

b. the unit should not clog easily, i.e., there should be no necessity to use water of high purity, as this in turn would require complicated and expensive filtering means;

c. the unit should be sufficiently small so that it can be mounted and transported easily.

Quite a number of solutions have been proposed,

some being more and some less satisfactory.

Thus there are already known units comprising substantially an outer tubular member and inner tubular member, oneof the members having formed thereon a continuous groove, which together with the complementary surface of the other member defines a continuously direction-changing water conduit and an inlet or outlet therefor. The unit may be part of the water supply line or a separate unit to be connected to the line. The conduit groove, which is preferably helical, follows the same direction as the pipe unit.

There is also known a trickle-feed unit which comprises an inner and an outer tubular member, wherein one of these members has formed in its surface a continuous groove extending altematingly from one end to the other end of the saidmember and vice versa, the groove being connected with the interior of the inner tubular member at one end and having an outlet at its opposite end.

BRIEF SUMMARY OF THE INVENTION An object of the present invention is to provide an emitting or dispensing unit as small as possible, without unduly decreasing the cross-section of the flow area in the groove, but at the same time reducing the pressure from the head as much as possible so as to attain an emission of irrigating water at very low flow rates.

According to the invention there is provided an irrigation trickler unit for connection to a pipe line comprising an outer tubular member and an inner tubular member disposed tightly therein, the surfacr of at least one of the members having a groove formation which '2 forms, with the continuous surface of the other tubular member, a continuous pathway including a plurality of axially-extending runs serially connected together at their ends so that the continuous pathway extends back and forth in an axial direction from one end to the other end of the tubular members, with each axial run spaced in the circumferential direction from the succeeding one. According to an important feature of the invention, the groove formation defining each of the axial runs includes a plurality of bends extending transversely of the axial run. Such bends form sharp turns which cause a change in direction of the flow of the water, each bend having a radius of curvature no greater than the width of the cross-section of the groove thereat. As a result, the resistance of flow increases along the pathway, and therefore the rate of water discharge at the open end of the unit is reduced to a great extent.

Many arrangements may be used for producing the foregoing flow-direction-changing bends and .tums.

According to one described embodiment, the groove formation forming the continuous pathway is defined by a plurality of parallelridges extending axially of the tubular members and spaced circumferentially from each other, each of the ridges including a plurality of spaced ribs extending transverselyof the ridges, the

ribs of one ridge extending into the space between the ribs of an adjacent ridge.v

According to another described embodiment, the groove formation forming the continuous pathway is defined by a plurality of parallel grooves extending axially of the tubular members and spaced circumferentially from each other, each of the grooves including narrow cross-section portions, the junctions of which form the flow-direction-changing bends and turns.

A discharge unit of this type may be installed by being inserted at intervals into the pipeline conducting the water (or fertilizing solution), or it may be set on the pipeline and flow-connected with it.

In the first case, the inner member is usually in-line with the sections of the pipeline and the liquid carried therein flows to its greater part through such inner tubular member, only part of the flow being deviated to the groove provided in the unit, to be emitted there from in the drip-or tricklelike manner.

In the second case, the unit is set. on the pipeline and its emitting groove is connected therewith.

As compared with the above mentioned known constructions, in the present proposed unit there is the advantage that the unit may be smaller, i.e., of shorter length, and the grooves may be wider as compared with the grooves in the known units. For this reason the water need not be filtered before entering and it does not matter if it carries impurities up to a certain size. Thus, passing the water through. a simple strainer should be sufficient.

In the known trickle dispensing units the water has to be filtered by passing it through a 200 mesh filtering screen. With a unit according to the invention, a simple strainer retaining foreign bodies above one-half mm diameter will suflice. Obviously, therefore, the unit according to the invention may be used not only for pure irrigation purposes but the liquid conducted in the respective'pipeline and emitted through the unit may contain fertilizers or other matter which it might be desirable to conduct to the soil or to the roots of plants. Accordingly, the emitter unit according to the present invention is not restricted to having one discharge opening only. On the contrary, it can be easily so constructed that there are several outlets, e.g., 2, 3, 4 or even more. In this case the terminal end of said groove is provided with the desired number of outlets. Moreover, said grooves may be also so designed that at their end they are not provided with an outlet but they proceed to a further groove which lengthens the travel of the water and increases the frictional resistance, which results in a slow dripping of the water.

The size of the angles of the bends is not a critical feature of the present invention, although an angle making a substantially complete U-turn is preferred. There are a great number of posibilities, all of them being within the scope of the present invention.

The emitter unit, according to the present invention, may be made of any of the conventional materials used for the manufacture of irrigation emitter units, e.g., plastic materials, metals, etc.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the annexed drawings. In the drawings:

FIG. 1 is a perspective view of one practical form of the new emitter unit, drawn on an enlarged scale;

FIG. 2 is a sectional view of the same unit as inserted into a pipeline;

FIG. 3 schematically shows the positioning of the emitter units within the pipeline;

FIG. 3a schematically illustrates the positioning of the units on a pipeline;

FIGS. 4, 5, 6, 7, 8 and 9 indicate schematically further possible forms of the groove within one of the tubular members.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning first to FIGS. 1 and 2, the new trickle emitter unit comprises an inner tubular member I which at both of its ends is provided with appropriately shaped end pieces la and lb for the connection to sections of a pipeline indicated by the numeral 2 in FIG. 2. The outside of the member 1 is provided with a continuous mazelike groove which extends from one end of the member to the opposite end and from here back to the first named end and so on. This groove is in communication with the interior of member I. In the example shown in FIG. 1 there are provided a number of radial holes or slots 4 which lead from the interior of member 1 to the outside, i.e., into the confines of the said continuous groove. In the example shown the said holes 4 lead into a circumferential depression 5 which is defined by two ring-shaped ribs 6. The diameter of holes 4 or the width of slots 4, as the case may be, is smaller than the width of the depression 5 and the continuous mazelike groove. Thus foreign bodies carried by the flow and of a size larger than the openings 4 will be carried along by the flow in the line 2 and will not enter the emitting unit. That is, foreign bodies that are too large to pass through openings 4 remain in the line and are carried away, while smaller bodies travel through the emitter unit and do not clog the passages therein. The advantage of this arrangement is that no filter is required for the emitting unit.

On the outside of the tubular member I extend a number of ridges 7 in axial direction from which branch off laterally extending short ribs 8; between 4 them these ribs and ridges form the said continuous mazelike groove the extension of which can be followed in the drawings.

From the extreme right hand opening 4 a short slot or nick 5' leads into the meandering groove as indicated by the arrows in FIG. LThe groove progresses in the axial direction, continuously turning to the right and to the left about the branched ridges 8 until the groove arrives at the lower end of the FIG. I to the bend wherein its direction is reversed, i.e., redirected to the upper direction.

In the drawings the reverse flow or extension of the groove is supposed to be at the side which is turned away from the person looking at the drawing. However, the flow reappears to view at the arrow x at the left hand top side of FIG. 1, the flow continuing in downward direction to the arrow y and again up and down as indicated by arrows, finally to arrive at the arrow 2 where the flow or the groove enters a ring-shaped depression 9 from which slots 11 lead into the open. The said tubular member is enclosed by a second sleeve shaped tubular member 10 which is indicated in the drawing by dash-dotted lines. Thus the said groove extending up and down between the two members I and I0 is fully closed and the only outlets therefrom are the slots 11.

The arrangement in actual use is illustrated by FIG. 3. The pipeline is indicated by the numeral while the units are indicated by the numeral 200. As can be seen, in a pipeline of whatever length a number of trickle emitting units may be inserted at whatever intervals from one another. Water or fertilizing solution or whatever else is conducted through the said pipeline and the liquid is continuously and slowly emitted at every one of the said units, the initial pressure from the head being of no or little influence on the emission rate.

It should be understood that certain changes would be within the scope of the invention. The openings 4 may be elongated slots. Instead of providing both connections la and lb at the inner member, one might be on the inner, and one on the outer member. The continuous maze formed by the grooveneed not be of the form shown in FIG. l and 2; it may be given any other configuration, as exemplified by the examples of FIGS. 4 8. As has been stated the said groove may be of any configuration, provided that is continues toand fro from one end of the unit to the other and that the sections of the groove intermediate the two ends aresubdivided by bends and turns into the circumferential direction of the unit alternatingly .to one side and the other, and that the bends be substantially of a radius equal to or smaller than the width of the cross-section of the groove. i

The change of direction of the flow may also be attained by providing the continuous groove with widenings arranged at distances along the groove, i.e., alternating narrow portions of the groove with wider ones. This is shown schematically in FIG. 9. A portion of the groove is indicated by the numeral 20. The groove has alternating narrow portions 21 and wider ones 22. Water flowing through such a groove and entering from a narrow portion into a wide one will spread in the wider portion, as indicated by the small arrows in FIG. 9, when passing from the wide, into the narrow portion the flow will again become constricted. In other words, the sharp corners at the transition from narrow to wide and from wide to narrow position change the direction of flow just as the bends described do. It is possible to improve this effect by providing boss like baffles in the centre of the side portions, as indicated by the broken lines.

Instead of inserting the units into the pipeline, as shown in FIG. 3, they may be set thereon and connected to the flow by a small connecting pipe, as shown in FIG. 3a.

While the unit as described in this specification and as shown in the drawings comprises two tubular members, it would be within the scope of the invention to compose the unit of two or more flat prism shaped bodies, which between them define the continuous groove extending in a mazelike manner.

I claim:

ll. An irrigation trickler unit for connection to a pipeline, comprising, an outer tubular member and an inner tubular member disposed tightly therein, a surface of at least one of said members having a groove formation which forms, with the contiguous surface of the other tubular member, a continuous pathway including a plurality of axially-extending runs, serially connected at their ends so that the continuous pathway extends back and forth in an axial direction from one end to the other end of the tubular members with each axial run spaced in the circumferential direction from the succeedin g one, the groove formation defining each of said axial runs including a plurality of flow-directionchanging bends and turns extending transversely of the axial run, each bend having a radius of curvature no greater than the width of the cross-section of the groove pathway thereat, said tubular members including an inlet opening communicating with one end of the continuous pathway and an outlet opening communicating with the other end of the continuous pathway.

2. A unit according to claim 1, wherein said groove formation forming said continuous pathway is defined by a plurality of parallel ridges extending axially of said tubular members and space circumferentially from each other, each of said ridges including a plurality of spaced ribs extendings transversely of the ridge, the ribs of one ridge extending into the space between the ribs of the adjacent ridge.

3. A unit as defined in claim 1, wherein said groove formation forming said continuous pathway is defined by a plurality of parallel grooves extending axially of the tubular members and spaced circumferentially from each other, each of the grooves including narrow cross-section portions forming the flow-directionchanging bends and turns.

4. A unit as defined in claim 11, wherein the inner tu bular member is formed with said groove formation on its outer surface.

5. A unit as defined in claim 1, wherein the unit includes a plurality of outlet openings communicating with said other end of the continuous pathway.

6. A unit as defined in claim 1, wherein said inlet opening is of a cross-section smaller than that of the groove formation. 

1. An irrigation trickler unit for connection to a pipeline, comprising, an outer tubular member and an inner tubular member disposed tightly therein, a surface of at least one of said members having a groove formation which forms, with the contiguous surface of the other tubular member, a continuous pathway including a plurality of axially-extending runs, serially connected at their ends so that the continuous pathway extends back and forth in an axial direction from one end to the other end of the tubular members with each axial run spaced in the circumferential direction from the succeeding one, the groove formation defining each of said axial runs including a plurality of flow-direction-changing bends and turns extending transversely of the axial run, each bend having a radius of curvature no greater than the width of the cross-section of the groove pathway thereat, said tubular members including an inlet opening communicating with one end of the continuous pathwAy and an outlet opening communicating with the other end of the continuous pathway.
 2. A unit according to claim 1, wherein said groove formation forming said continuous pathway is defined by a plurality of parallel ridges extending axially of said tubular members and spaced circumferentially from each other, each of said ridges including a plurality of spaced ribs extendings transversely of the ridge, the ribs of one ridge extending into the space between the ribs of the adjacent ridge.
 3. A unit as defined in claim 1, wherein said groove formation forming said continuous pathway is defined by a plurality of parallel grooves extending axially of the tubular members and spaced circumferentially from each other, each of the grooves including narrow cross-section portions forming the flow-direction-changing bends and turns.
 4. A unit as defined in claim 1, wherein the inner tubular member is formed with said groove formation on its outer surface.
 5. A unit as defined in claim 1, wherein the unit includes a plurality of outlet openings communicating with said other end of the continuous pathway.
 6. A unit as defined in claim 1, wherein said inlet opening is of a cross-section smaller than that of the groove formation. 